Magnetic characteristics of the magnetic recording medium can be improved by, for example, orientating acicular particles of magnetic powder having magnetic anisotropy along the longest axis of the particle in the longitudinal or traveling direction of a magnetic layer. However, there is an upper limit of recording density in the magnetic recording medium having the magnetizing component in the longitudinal direction of the magnetic layer. That is, as the recording density of signals increases, the demagnetizing field in the magnetic recording medium increases and, in turn, decreases and a rotation of residual magnetization or remanence occurs so that it becomes difficult to read out the signals recorded in the magnetic recording medium.
Recently, a vertical magnetic recording system has been recognized as a suitable system for high density recording since in this system the influence of the demagnetizing field decreases as the recording density increases. For example, it is proposed to vertically record signals by using barium ferrite magnetic powder having a chemical comusing position of BaO.6Fe.sub.2 O.sub.3 each particle of which is of a hexagonal plate shape and has magnetic anisotropy in a direction perpendicular to the plate plane, and orientating the particles parallel to the magnetic layer so as to make use of the magnetic component in the direction perpendicular to the plate plane.
However, with the magnetic recording medium using the above described barium ferrite, it is difficult to satisfactorily record or reproduce the signals. This may be because the barium ferrite has too large a coercive force to be used in the magnetic recording medium. In order to decrease only the coercive force without deteriorating saturation magnetization, it is proposed to add Co or Ti to the barium ferrite in the production step thereof so as to substitute a part of the iron elements with these elements. However, when iron elements are unadequately substituted, for example, unhomogeneously substituted, the direction of the magnetic easy axis of magnetization, which should be in the direction perpendicular to the plate plane, changes into a direction parallel to the plane, that is, the magnetic particle is converted into a so-called planer type ferrite magnetic powder. In the planer type ferrite magnetic powder, the vertical magnetic anisotropy is deteriorated so that the magnetic recording medium comprising such planer type ferrite magnetic powder has deteriorated characteristics, particularly reduced maximum output level (M.O.L.) in a range of shorter wavelength. In an extreme case, the vertical recording and reproducing cannot be carried out.